Polarization States of Light and Their Quantum Tomography

I. N. Agafonov, Maria V. Chekhova, T. Sh. Iskhakov +2 more

Polarization quantum tomography is performed on 4-mode squeezed vacuum states. Three-dimensional polarization quasiprobability functions are obtained and compared to that of an equal intensity coherent state. These distributions clearly demonstrate the difference in the polarization properties of the considered states. The reconstruction quality of the coherent state distribution is also analyzed by comparing the theoretically and experimentally obtained shapes for this state.

Zavatta A., Valentina Parigi, Bellini M.

V. P. Karassiov

Methods of quantum tomography of light polarization are discussed as indirect measurements of the polarization density operator R̂ describing only polarization properties of quantum light. They are shown to be adequately formulated by means of quasi — spectral expansions of R̂ in partially‐orthogonal projectors determining spectral resolutions of some tomographic observables (“measurers” of R̂). Probabilistic interpretations of results obtained are briefly discussed.

V. P. Karassiov

Zhiqiang Luo, Xinghua Li, Yuwei Lan +4 more

Abstract We research the polarized dressing control of biphotons interference and quantum tomography. Different biphotons counting rates are obtained by different polarization dressings of incident beams of lights. We calculated the counting rates of all polarized dressing schemes. The counting rate of circularly polarized dressing has been observed with shorter period of oscillation and a longer coherence time when compared with linear polarization. Since, the different polarization dressings result in different modules of third-order nonlinear susceptibilities and different linewidths. Thus, we can adjust the dressing field by changing the polarization of the incident beam of light to obtain controlled pair of photons with desired longer coherence time. Based on that, we study the impact of the two dressing fields which cause the third-order nonlinear susceptibility to be different. In the absence and presence of external dressing field, the biphoton coincidence rate is completely different. By performing quantum tomography, we get various Werner-states and the polarization states of incident lights, this also helps in comprehensive characterization of output state. Further, we define the interference visibility for different polarized dressed states. The visibility of the circularly polarized dressing field is found to be larger when compared with linearly polarized dressing field. Thus, we can obtain photons with controllable coherence time and desired visibility with different polarization schemes to uncover the indistinguishability of photon interference and promote the study of quantum optics.

Silvania F. Pereira, Gerd Breitenbach, Stephan Schiller +1 more